Sum Of Odd Numbers Proof

Request a proof about odd numbers with a DeepSeek reasoning stage and an OpenAI response.

Demonstrates DeepSeek-backed reasoning for mathematical proofs.

DeepSeek retired the deepseek-reasoner alias after July 24, 2026. Before running this archived example, replace DeepSeek(id="deepseek-reasoner") with DeepSeek(id="deepseek-v4-flash") in the saved program. The main OpenAI model remains a separate call, so both provider keys are required. See the DeepSeek V4 migration notice.

mathematical_proof.py
"""
Sum Of Odd Numbers Proof
========================

Demonstrates DeepSeek-backed reasoning for mathematical proofs.
"""

from agno.agent import Agent
from agno.models.deepseek import DeepSeek
from agno.models.openai import OpenAIResponses

# ---------------------------------------------------------------------------
# Create Agent
# ---------------------------------------------------------------------------
task = "Prove that for any positive integer n, the sum of the first n odd numbers is equal to n squared. Provide a detailed proof."

agent = Agent(
    model=OpenAIResponses(id="gpt-5.6"),
    reasoning_model=DeepSeek(id="deepseek-reasoner"),
    markdown=True,
)

# ---------------------------------------------------------------------------
# Run Agent
# ---------------------------------------------------------------------------
if __name__ == "__main__":
    agent.print_response(task, stream=True, show_full_reasoning=True)

An explicit reasoning_model runs as a separate, tool-free reasoning stage before the main model response. show_full_reasoning=True displays the reasoning data Agno receives; it cannot reveal a provider's private internal trace. Some adapters use the reasoning stage's answer text when separate reasoning content is unavailable. A failed reasoning stage can still be followed by a main-model answer, so a completed run alone does not prove the reasoning stage succeeded.

Run the Example

Set up your virtual environment

uv venv --python 3.12
source .venv/bin/activate

Install dependencies

uv pip install -U agno openai

Export your API keys

export DEEPSEEK_API_KEY="your_deepseek_api_key_here"
export OPENAI_API_KEY="your_openai_api_key_here"

Run the example

Save the code above as mathematical_proof.py, then run:

python mathematical_proof.py

Full source: cookbook/10_reasoning/agents/mathematical_proof.py